Integrated interconnected porous and lamellar structures realized fast ion/electron conductivity in high-performance lithium-sulfur batteries

Abstract

The practical application of high-energy-density lithium-sulfur (Li-S) batteries have been highly praised for energy storage devices, while are largely hindered by the “shuttling effect”. Herein, core-shell carbon spheres composed of interlinked porous core and lamellar shell were designed to restrain the polysulfide shuttling. The microporous structure with pore size of around 1 nm effectively trap lithium polysulfides. Furthermore, the interconnected porous core shortens the ion transfer distance and the lamellar carbon shell endows the carbon spheres with fast electron conduction, finally facilitating polysulfide conversion kinetics. Therefore, the Li-S batteries with the carbon spheres as the interlayer show high discharge specific capacity of 1002 mAh/g at 2 C with 574 mAh/g remaining after 600 cycles, and high areal capacity of 5.48 mAh/cm2 with sulfur loading of 4.67 mg/cm2 at 0.1 C. The corresponding pouch cells also exhibit stable cycling stability with an initial discharge specific capacity of 1082 mAh/g at 0.1 C.